Seeking guidance on configuring a multi-tenancy WordPress setup where the core remains unified, yet each tenant operates with its own database and theme. Specifically interested in implementing Sage 10 for theme development and leveraging Composer for efficient management of the entire stack.
You’ve come to the right place! Bedrock can do what you’re looking for, and Sage is a great starter theme to build a multisite with.
Start with the documentation for Bedrock.